Dr. Travis Dekker:
Welcome to the Arthroscopy Association's Arthroscopy Journal podcast. The views expressed in this podcast do not necessarily represent the views of the Arthroscopy Association, nor the Arthroscopy Journal, and they're not meant to be used as treatment recommendations for patients.
Welcome, everyone. I'm Dr. Travis Decker, coming from the United States Air Force Academy. I'm here and joined today by a good and dear friend and colleague of mine, Dr. Andrew Sheean. He's a clear up-and-coming star in our sports world coming from San Antonio Medical Center. And like myself, he's an active duty Air Force surgeon and has taken a keen interest in both shoulder and knee surgery, specifically optimized returning servicemen and women back to active duty safely. He's a research savant, asking provocative and practical questions that are helping shape our current treatment strategies.
Today we'll be discussing his April 2023 article from ASMAR, entitled The Glenoid Track Paradigm Does Not Reliably Affect Military Surgeons' Approach at Managing Shoulder Instability. Welcome to the podcast, Andy.
Dr. Andrew Sheean:
Travis, thanks for having me. And it's exciting to be doing it under these unique circumstances. So the listeners know, we're actually sitting here at an intermission of the annual AANA Society of Military Orthopedic Surgeons Knee Arthroscopy course here at the Orthopedic Learning Center in Rosemont. So I can't think of a better opportunity to talk to you about taking care of active duty military patients.
Dr. Travis Dekker:
Yeah, it's a unique opportunity, and it's great that SOMOS and AANA has continued the relationship. And it's a privilege to be with you today and being able to speak about something that I think we, as military orthopedic surgeons, get to see a lot of. And I think a lot of the listeners have taken a lot of your work and then our predecessors, between Doctors Provencher and Tokish, to help guide our treatment strategies.
And, Andy, can you first take us a little bit through your background and interest in shoulder instability? Specifically discussing how you've evolved in the evaluation of glenoid bone loss, and how you've seen the algorithm of treatment of glenoid bone loss changing since we've started our young and early careers?
Dr. Andrew Sheean:
Yeah. I think that being a military surgeon, this has got to be at the forefront of what it is that we're thinking about and the types of patients that we're comfortable in treating, given the nature of the work that so many of our patients do. I'd also be remiss if I didn't acknowledge my mentors. You already mentioned some giants in the field, J.T. Tokish, Matt Provencher, a strong military lineage, but also too my mentors during my fellowship training at the University of Pittsburgh, Albert Lin, Jim Bradley, Bryson Lesniak, all of those individuals have certainly colored the way that I think about taking care of these patients with these complicated injuries.
You already hit on it. I think that we now, much more so than the past, appreciate the role that bone loss and bipolar bone loss plays in the pathomechanics of these injury patterns. And so it's been exciting to watch and to participate to a lesser extent over the last five to seven years in the evolution of the concepts that have been elucidated and described as the bipolar bone loss paradigm.
Dr. Travis Dekker:
Well, one thing that struck me is recently at a meeting, you and I sat across the table from one another, trying to figure out that we have waffled back and forth about evaluating glenoid bone loss specifically, and that it has played a large part into how we treat our patients. We've gone from numbers with Burkhart from 20 to 25%, down to as little as 13.5%, sometimes 10% in papers, which as we know is literally millimeters of difference.
You wrote a great commentary in Arthroscopy that went through the inconsistency of how we even manage or evaluate this, much less manage this. Can you hit on how maybe what you found and what you spoke about then and how it relates to the findings of your paper?
Dr. Andrew Sheean:
I appreciate you bringing up that commentary, it was fun to write. And it's really extraordinary when you think about it, when you think about the ways in which the algorithm has evolved and the different routes that we take, based upon literally millimeters of measurement. And so I think that while my initial comments not withstanding about the importance of bone loss, it really underscores the importance of taking a step back and considering bone loss, but also considering a myriad of patient factors, associated soft tissue injuries.
And we can probably get into that a little bit, but thinking about anterior-inferior instability not as simply a unidirectional problem, but a bidirectional problem. And understanding that there's things like the plastic deformation of the posterior capsule, and how that should probably affect our threshold for adding fixation and stabilization stitches in the back of the glenoid. I mean, we could go on and on. There's so many exciting things to talk about it, but it's certainly been an evolution.
Dr. Travis Dekker:
Well, let's start hitting it on this paper specifically. Military surgeons do a lot of shoulder instability. I think a lot of the times we, as surgeons, we go to conferences, we raise our hands and we sit on our laurels, saying that we reliably will treat patients based off of specific criteria and that we're always going to ... Regardless of certain demographics and factors, we're going to stick to the numbers and stick to the evidence to treat patients in a specific way. But do you mind going a little bit through your findings from the paper and some of the takeaways?
Dr. Andrew Sheean:
Sure. We used the MOTION database, which was a database that was stood up about eight years or so ago now through the visionary work of Jon Dickens and others. And basically it afforded military surgeons the opportunity to collaborate across military treatment facilities and collate their experiences in terms of surgical decision-making and patient-reported outcomes, in order to help us get a better idea from the standpoint of what the clinical outcomes are and associated with a number of surgical procedures. So we used the MOTION database in this context to evaluate the types of things and the types of patient-specific factors that were informing the ultimate treatment approaches for military surgeons taking care of glenohumeral instability.
Over 500 patients. As far as I know, this is probably the largest series, certainly in the American literature, of a military experience. And we can talk about some of the limitations in terms of what the MOTION database does and does not include. We did not look at any patient-reported outcomes. We focused exclusively on some basic demographic parameters, and then measurements of glenoid bone loss, some morphologic descriptions of the Hill-Sachs lesion, and then obviously the location of these labral lesions. But then using these parameters we were able to make some general observations in terms of the types of procedures that military surgeons were performing.
I think that there were some very interesting findings. Not unsurprisingly the overwhelming majority of these surgical stabilization procedures were done arthroscopically, which I think reflects the state of the art, and I think to a large extent reflects the way that orthopedic surgeons and certainly military surgeons are trained. I was really surprised though by the number of, or I should say the relatively small number of LatarJet procedures that were performed over this interval.
We looked at the shoulder stabilization periods ranging from November of 2016 until October of 2021. And in that database, which I would acknowledge is not inclusive, you have to imagine that there are a number of shoulder stabilization procedures that for whatever reason didn't make it in the MOTION database, but I was really surprised to see that only 39 Latarjet procedures were performed. And only 58 glenoid augmentation procedures, whether that be through a free distal tibia allograft or iliac crest and everything like that. And so to your point exactly, it was surprising to see how infrequently that procedure was performed. So I think that that was probably the thing that was most surprising to me about our findings.
I think it's worth mentioning, and this has been borne out in previous papers Jeanne Patzkowski has published on the prevalence of combined labral lesions. And so like I mentioned earlier, I think now there's enough evidence out there to suggest that at least within a military population, if you think that a labral lesion is just in the front or just in the back, it probably is not the case. Greater than 50% of the patients in this series had in fact combined lesions, whether that be a SLAP tear propagating down around the back, that so-called Type VIII SLAP tear, or an anterior posterior lesion.
And so I think that we should just really take that information as military surgeons and cage us and get us ready in order to tackle more complicated instability problems and just the unilateral directional instabilities.
Dr. Travis Dekker:
Well, that's a great summary, and wondering if you could also hit on ... I find it a little bit of surprising that on-track, off-track has been a very popular way to critically evaluate shoulder instability in those that will go on to recurrence, but really to help us dictate what we do and don't do in the operating room. I think that over this period remplissage has definitely become more popularized. I think as Dr. Tokish has been up on the podium, it's a much easier procedure to do, and so it lends itself for more surgeons being able to do this procedure.
But as you've shown in your results that having a Hill-Sachs lesion, it 79% of the time increased the likelihood of having that done, but that an off-tract Hill-Sachs lesion did not predict the decision-making process. Wondering if you can speak to those two points, and specifically, is the on-track, off-track dictating what we do?
Dr. Andrew Sheean:
Well, I think in short these data would suggest, no, not entirely. Now, I did mention that we went back and looked, starting in 2016, and from a historical perspective as you know, the bipolar paradigm and the extent to which remplissage has begun to play a role in that paradigm, really got started in the mid 2010s or so. We did not look at a temporal analysis and to see the extent to which perhaps the frequency of those procedures increased over the interval in which that we looked. It would be interesting to repeat the study now because I think I would be willing to bet that those numbers would certainly be increased at this point.
But yeah, it was certainly surprising to see. Yeah, so I think that this very well, these findings, may be a historical point. And again, I think if we repeated this, those findings would be a lot different now, but certainly a surprising finding for sure.
Dr. Travis Dekker:
Andy, you're very intelligent in the way that you approach these types of studies. And when I'm looking at the statistics and how you guys were going through this analysis, you bring up this decision tree analysis. For us mere mortals, can you at least describe a little bit what this decision tree analysis is in layman's terms?
Dr. Andrew Sheean:
I'll do my best, but I probably should be chaperoned by our, you used the term savant earlier, I'll use it again, our savant, Matthew Tenan, who did the lion's share of the statistical analysis in this. But basically, in very broad terms, a decision tree analysis takes the frequency which certain things happen, and then imputes or forecasts the likelihood of subsequent things happening in a future scenario, if that makes sense.
And so when we talk about the thresholds and things like that, for example, the decision tree analysis would suggest that the threshold of 17% would drive a surgeon's decision to proceed with either an open or an arthroscopic procedure, particularly an open bone grafting procedure, that is a prediction or that is a forecast based upon a model that has been constructed with the counts and the data that were put into the model, if that makes sense. And if you're looking for much more clarification beyond that-
Dr. Travis Dekker:
All right. Well, maybe highlighting back to the question of on-track and off-track, are we as military surgeons doing our patients a disservice, where the decision tree analysis is stating that off-track legions are not predicting the type of operation? And why do you think that the on-track, off-track equation is not dictating our care? It made me curious to think that, are we just simply ... Is it the labor of going through the calculations, that in a busy and active clinic, that we see a primary patient with primary shoulder instability, and so the automatic go-to is, "Hey, I'm going to do a labral repair, plus or minus remplissage?"
Because there are now papers from Denard's work supporting the use of remplissage, even in off-track lesions. But why would it, in such a high-volume practice where we see high-demand patients, these significant findings, tests, not predict what we're doing and giving to patients?
Dr. Andrew Sheean:
I think that we've hit on a little bit about the variability of these measurements, and we can talk about in inter and intra-observer reliability. I mean, maybe some of these measurements are made when the patient comes for their pre-op appointment and a surgical plan is made, and then the measurements are made day of. And I think that to some extent the variability between those measurements is a reflection of the fragility of maybe some of these approaches to decision-making.
I'm glad that you brought up Patrick Denard's work. I think those findings are very compelling and would suggest that perhaps Bankart remplissage, even in more advanced magnitudes of glenoid bone loss, may be certainly a reasonable approach. But I think that if one of the take-homes from this paper is military surgeons need to pay a little bit closer attention to these things and really walk the walk, then I'm okay with that. And I think that that's why courses like AANA/SOMOS course, in which we can really hone our arthroscopic skills ... I mean, this year it's a knee course. Next year it's going to be a shoulders course. I mean, maybe this is a focus area for us as leader arthroscopic teachers in the military to be doing our part to take these results and take it as a way to get better. And get military surgeons better, and get them better at making the right decisions. And making decisions that are based upon solid rationale and not based upon skills or the limitation of skills or a reluctance to do something that are novel.
And so I think that's why AANA has always been at the forefront and advancing arthroscopic skills teaching. And so I think that's why so many of these things are important and salient today.
Dr. Travis Dekker:
Well, lastly, Andy, I wanted to ask you, you are at an academic institution, you're actively teaching residents. We've talked about the importance of glenoid bone loss. We are using through your decision tree analysis, a measurement of 17%. How are you teaching your residents how to measure glenoid bone loss?
Dr. Andrew Sheean:
Yeah. I'm not really taking any liberties in terms of the measurements and how these things are quantified. I think that the majority of these cases and measurements are made on MR, very low threshold, however you get a CT scan to calculate the glenoid bone loss on the CT.
I think though that there continues to be a lot of really interesting work done in further clarifying, or delineating I should say, the differences between different morphological patterns in Hill-Sachs lesions. Albert Lin has really been on the vanguard of describing several new parameters to include the distance to dislocation. Which on the face of it, the cynic would say, "Well, you guys aren't even using the on-track, off-track paradigm to begin with." And to which I'd say that's somewhat valid. But at the same time, I think that it's inspiring to see thought leaders taking these things to the next level. He's also just recently presented several weeks ago on the importance of the superior to inferior dimensions of the Hill-Sachs lesion.
And so I think it's very much, it's a stay-tuned situation, but I think that we owe it to our patients to be students of this game, so to speak. And be asking of ourselves and of our colleagues to continue to get better and employ the skills necessary in order to treat these difficult problems.
Dr. Travis Dekker:
All right, Andy, as we sit here, very much appreciate you doing this podcast with me. I know that you're on the vanguard of and forefront of military, specifically as it comes to some of our more common injuries in pathology seen in the knee and shoulder. And so today we were really able to go through Andy's ASMAR article published in April 2023, entitled The Glenoid Tract Paradigm Does Not Reliably Affect Military Surgeons' Approach to Managing Shoulder Instability. This article can be currently accessed at www.arthroscopyjournal.org.
And once again, the views expressed in this podcast do not necessarily represent the views of the Arthroscopy Association, nor the Arthroscopy Journal, and they're not meant to be used as treatment recommendations for patients. Thank you all for joining us and have a great evening.
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